A. Field of Invention
The present invention is directed generally to a method of production of value-added, biobased chemicals, derivative products, and/or purified bioglycerin from bioglycerin. The present method described herein provides methods for desalinating, decolorizing, and/or concentrating bioglycerin for the production of biobased chemicals, derivative products, and/or purified bioglycerin.
B. Description of the Related Art
The world currently faces depletion of fossil fuels while demands for these fuels are ever increasing. Petrochemicals provide an energy source and a component of the majority of raw materials used in many industries. In fact, approximately 95% of all chemicals manufactured today are derived from petroleum. However, this heavy reliance upon fossil fuels is creating harm to the environment. The burning of these fossil fuels has led to the pollution of air, water and land, as well as global warming and climate changes. Through the use of fossil fuels, the environment has been harmed, perhaps irreparably, in an effort to meet the nearly insatiable demand for energy and manufactured products. Fossil fuels are a finite natural resource, with the depletion of readily available oil reserves across the globe; the supply chain has shifted to more complex and environmentally risky production technologies. A reduction and conservation of fossil fuels is clearly needed. Some alternatives to fossil fuels, like solar power, wind power, geothermal power, hydropower, and nuclear power, are used to a degree. However, a more efficient use of renewable resources is always being sought.
In particular, biofuels, which come from a renewable, carbonaceous source, are targeted to become one of these more efficient resources. In the demand for fossil fuels, biodiesel, a type of biofuel, has emerged as an environmentally friendly and potentially inexhaustible alternative to petroleum diesel, particularly during an oil crisis, a surge in crude oil prices or political unrest in the oil producing regions of the world. This renewable and clean-burning diesel replacement is said to reduce our dependence on foreign petroleum and create new employment within the green industry.
Biodiesel is considered as an environmentally friendly, renewable transportation and heating fuel relative to petroleum diesel. Biodiesel is made from agricultural oils and animal fats (or tallow). In addition, the triglyceride-rich waste streams of rendering and cooking operations find use in biodiesel production.
Biodiesel consists of mono-alkyl esters of long chain fatty acids that are produced by reaction of a triglyceride with an alcohol. This process yields biodiesel through a hydrolysis and/or transesterification reaction during which bioglycerin is cleaved as a by-product from the triglyceride. Thus, the process yields two products: biodiesel and crude bioglycerin. Crude bioglycerin is formed in approximately 1 part to each 10 parts of biodiesel. In the pure form, glycerin is a colorless, viscous liquid; however, crude bioglycerin may be a yellowish to dark brown liquid. It may be a clear to a turbid liquid, or have a syrup-like consistency. Crude bioglycerin may contain significant amounts of particulate matter, dissolved inorganic salts, alcohol and water, fatty acids and other impurities from the biodiesel process. Because of the high content of these impurities, uses for crude bioglycerin are limited while escalating global biodiesel production is culminating in a market glut for this by-product. Additionally, varying purity levels of the crude bioglycerin due to different feedstock sources of the biodiesel as well as different levels of in-process control among biodiesel producers do not provide a uniform approach to treating the bioglycerin. Even if the crude bioglycerin is treated, the purification of crude bioglycerin historically has been too expensive and commercial implementation of a crude bioglycerin purification process is yet to prove economical at large scale.
Because crude bioglycerin is expensive to purify and market demand for this material is limited, it is often sold at a significant discount relative to the price of petroleum-based glycerin. In lieu of a market outlet, crude bioglycerin would quickly accumulate as an unwanted waste product of biodiesel production with associated disposal costs. Although this green process of creating biodiesel fuel is grounded upon the sustainable use of renewable resources, the process unfortunately generates a low-value by-product that diminishes the overall green value of biodiesel production. However, a purified glycerin from the production of this biofuel would provide an even greener process as well as become a potential additional revenue stream for biodiesel producers. Such purified bioglycerin could compete and function as a green replacement to petroleum-derived glycerin and/or serve as a renewable feedstock for the production of value-added, derivative products, biobased chemicals, and/or purified bioglycerin.
In the pure form, glycerin has many uses. It is used in the food and beverage industry as a humectant, sweetener, solvent, preservative, filler, emulsifier, and thickening agent. It also has several uses in the personal care and pharmaceutical industries where it functions as a lubricant, humectant, laxative, bacteriostat, moisturizer and pharmaceutical excipient. It is a well-known component of glycerin soaps. It also has applications in tobacco, polyether polyols, alkyd resins, paints, coatings, lubricants, textiles, paper, biological research, fabric softeners, cellophane, explosives, and epoxy resins. Targeted emerging applications for glycerin include its conversion into commodity chemicals, like 1,2-propanediol and 1,3-propanediol, and into fine chemicals like epichlorohydrin, glycidyl ethers and glycidyl esters. Once implemented, these applications are expected to further improve global market demand for glycerin. Overall, a purified bioglycerin from biodiesel production could serve as a feedstock for production of value-added, biobased chemicals and as a means to reduce costs associated with waste stream disposal.
The present invention provides methods for purifying crude bioglycerin and converting bioglycerin into value-added, biobased chemicals while minimizing waste products.